System , method and apparatus for making tapered looped suture

ABSTRACT

A system and method for forming a looped suture having a tapered cut is provided. The system includes a base for selectively retaining a portion of thread, a clamping device for receiving a first end of the thread, a tensioning device for receiving a second end of the thread, and a welding/cutting assembly configured to join a first section and second section of the thread to form a loop and to form a tapered end on the first section of the thread. A die for forming a looped suture having a tapered cut is also provided.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a divisional application of U.S. patentapplication Ser. No. 12/582,982, filed Oct. 21, 2009, which claimsbenefit of and priority to U.S. Provisional Patent Application Ser. No.61/108,581, filed Oct. 27, 2008, the entire disclosure of eachapplication is incorporated by reference herein.

BACKGROUND

1. Technical Field

The present disclosure relates to a method of forming a looped suture.More particularly, the present disclosure relates to a method of forminga looped suture having a tapered cut.

2. Background of Related Art

A method for forming a loop in a suture during a wound closing procedureis known. The method includes using a device to ultrasonically weldtogether first and second ends of a suture that have been receivedthrough opposing sections of tissue. The welding of the suture endsforms a loop that retains the opposing sections of tissue adjacent oneanother, thereby assisting in the healing of the wound. Because the loopis formed in She suture after the suture has been received throughtissue of a patient, to be useful for any practical purpose, theultrasonic device must be configured for handheld operation. In thismanner, a clinician may operate the device in an operating room or adoctor's office. As with all handheld devices, the configuration andeffectiveness of the handheld ultrasonic device is limited by its sizeand weight. The limitations created by the size and weight restrictionsof the device become apparent during the forming of a loop on a sutureprior to engagement with tissue.

Therefore, it would be beneficial to have a system and method for moreeffectively forming a loop on a suture prior to engagement of tissuewith the suture. It would be further beneficial if the system and methodcould form a tapered end on the loop.

Accordingly, a system for forming a looped suture basing a tapered cutis provided. The system includes a base for selectively retaining aportion of thread, a clamping device for receiving a first end of thethread, a tensioning device for receiving a second end of the thread,and a welding/cutting assembly configured to join a first section and asecond section of the thread to form a loop and to form a tapered end onthe first section of the thread.

The base may include a suture nest a pin retaining member, a pin, and apin locking member. The pin retaining member may be pivotally mounted tothe base. The pin may be configured to receive a portion of the threadthereabout. The base may include at least one channel for receiving atleast a portion of the second section of the thread. The welding/cuttingassembly of the system may include a die having a suture engagingportion and a suture cutting portion. In one embodiment, thewelding/cutting assembly is moved relative to the base. Alternatively,the base is moved relative to the welding/cutting assembly. Thewelding/cutting assembly is configured for operable connection to anultrasonic generator.

A method of forming a loop in a thread is also provided. The methodincludes the steps of providing a loop forming system including, a basefor securely retaining a thread to be formed, a clamp for retaining afirst end of the thread, a tensioning member for retaining a second endof the thread and applying tension to the thread, and a welding/cuttingassembly for forming a loop having a tapered end in the thread, securinga portion of the thread to the base such that a first section of thethread is maintained adjacent to a second section of the thread,approximating the welding/cutting assembly and the base towards eachother, fusing the first section of thread to the second section ofthread, cutting a tapered end on a proximal end of the first section ofthe thread, approximating the welding/cutting assembly and base awayfrom each other, and removing the formed suture tram the base. Thewelding/cutting assembly may include a die having a thread engagingportion and a thread cutting portion.

A die for forming a looped suture is also provided. The die includes abase portion, a connecting portion extending from the base portionconfigured for selectively engaging an ultrasonic device, and a suturemount extending from the base portion opposite the connecting portion.The suture mount includes a thread engaging portion and thread cuttingportion configured to form a loop having a tapered end in a thread. Theconnecting portion may include threads. The thread engaging portion maybe flat. The base portion may be configured to be selectively engaged bya removal/installation tool.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and consulate apart of this specification, illustrate embodiments of the disclosureand, together with a general description of the disclosure given above,and the detailed description of the embodiment(s) given below, serve toexplain the principles of the disclosure, wherein;

FIG. 1A is a side view of a looped suture including a tapered portion;

FIG. 1B is a cross-sectional end view of the looped suture of FIG. 1A,taken along line 1B-1B;

FIG. 1C is an enlarged side view of portion 1C of FIG. 1A;

FIG. 2A is a front view of a base for using in the tapered loop formingmethod of the present disclosure;

FIG. 2B is a side view of the base of FIG. 2A;

FIG. 2C is a top view of the base of FIGS. 2A and 2B;

FIG. 3A is a side view of the base of FIGS. 2A-2C loaded with a sutureand including a welding assembly, a suture retaining assembly and asuture tensioning assembly;

FIG. 3B is a top view of the loaded base of FIG. 3A;

FIG. 4A is front view of a die for forming a looped suture in accordancewith an embodiment of the present disclosure:

FIG. 4B is a side view of the die of FIG. 4A;

FIG. 4C is top view of the die of FIGS. 4A and 4B;

FIG. 4D is an enlarged view of portion 4D of FIG. 4B;

FIG. 4E is an enlarged cross-sectional view of portion 4E of FIG. 4A;

FIG. 4F is a perspective view of the die of FIGS. 4A-4E;

FIG. 5 is a cross-section view of the loaded base of FIGS. 3A and 3B;

FIGS. 5A and 5B are enlarged views of portion 4 of FIG. 3C, with thesuture in pre-welded (FIG. 5A) and post-welded (FIG. 5B) configurations;

FIG. 6A is a enlarged partial cross-sectional side view of a loopedsuture forming assembly according to an embodiment of the presentdisclosure, prior to forming of the loop;

FIG. 6B is an enlarged partial cross-sectional side view of the sutureforming assembly of FIG. 6B, during forming of the loop; and

FIG. 6C is an enlarged partial cross-sectional side view of the sutureforming assembly of FIGS. 6A and 6B, following formation of the loop.

DETAILED DESCRIPTION

A method for forming a looped suture including a tapered cut is hereindescribed. Referring initially to FIGS. 1A-1C, a looped suture formed inaccordance with a method of the present disclosure is shown generally aslooped suture 10. Suture 10 is formed from a monofilament thread 11;however, it is envisioned that suture 10 may be formed from braidedthreads, multifilament threads and other surgical fibers. Although shownhaving a circular cross-sectional geometry, the cross-sectional geometryof thread 11 may be of any suitable shape, e.g., round, elliptical,square, flat, octagonal, and rectangular. Thread 11 may be formed ofdegradable materials, nonbiodegradable materials, and combinationsthereof. Thread 11 may be formed using any technique within the purviewof those skilled in the art, such as, for example, extrusion, moldingand/or gel spinning.

With reference to FIGS. 1A and 1B, looped suture 10 includes a loop 12formed on a distal end 10 b thereof. Loop 12 forms a substantiallyteardrop shape and may be formed of any size. A first section 13 ofmonofilament thread 11 overlays a second section 14 of thread 11 to formloop 12. The adjacent surfaces of first and second sections 13, 14 forma joined segment or joint 15. As shown, joined segment 15 extends beyondfirst section 13 of thread 11. In this manner, first and second sections13, 14 of thread 11 are less likely to separate or peel away from eachother as looped suture 10 is pulled through tissue (not shown).

As will be described in further detail below, first and second sections13, 14 of thread 11 are welded together to form joined section 15. Inthis manner, first and second sections 13, 14 of thread 11 are locallyheated until each fuses to form joined segment 15. Various types ofenergy may be used to locally heat first and second sections 13, 14 toform joined segment 15, including, RF, ultrasonic, laser, electrical arcdischarge, and thermal. Alternatively, first and second sections 13, 14of thread 11 may be joined using glue, epoxy or other adhesive.

With particular reference to FIG. 1C, a proximal end 13 a of firstsection 13 is angled to form a tapered surface 17. Tapered surface 17angles downwardly towards proximal end 10 a of looped suture 10. Taperedsurface 17 may form an angle between zero degrees (0°) and ninetydegrees (90°), and preferably between about fifteen degrees (15°) toabout sixty degrees (60°). Tapered surface 17 facilitates insertion ofloop 12 into or through tissue (not shown). In one embodiment, taperedsurface 17 is formed such that joined segment 15 extends beyond firstsection 13 of thread 11. In this manner, tapered surface 17 forms asmooth transition with second section 14 of thread 11, therebydecreasing the likelihood that first and second sections 13, 14 mightseparate or peel away from each other as looped suture 10 is pulledthrough tissue.

Although shown having a substantially planar taper, tapered surface 17may include any number of configurations. For example, tapered surface17 may be beveled, may include a laterally and longitudinally concavetaper, may include a laterally and longitudinally convex taper, or mayinclude any combination thereof. The angle and/or configuration oftapered surface 17 may be selected depending on the tissue being suturedand/or the depth loop 12 is desired to be received within the tissue(not shown).

A system for forming loop 12 on distal end 10 b of looped suture 10 willnow be described with reference to FIGS. 2A-6C, and is shown generallyas system 100. System 100 includes a fixture member or base 110, asuture retaining member 120 (FIG. 3A), a suture tensioning member 125(FIG. 3A), and a welding/cutting assembly 130 (FIGS. 3A and 3B).

Referring initially to FIGS. 2A-2C, base 110 includes a platform 112, asuture nest 114, a pin retaining member 116, a pin 116 a extending frompin retaining member 116 and a pin lock 118. Platform 112 includes oneor more openings 112 a for securing base 110 to a workstation (notshown) using bolts 112 b or other suitable fixation means. As shown,suture nest 114 is integrally formed with platform 12. Alternatively,suture nest 114 is releasably attached or securely affixed to platform112. Nest 114 includes one or more channels 115 extending across a topsurface 114 a thereof. As will be described in further detail below,channels 115 are configured to partially receive a portion of suturethread 11, including second section 14 (FIG. 1C). Nest 114 furtherincludes raised outer portions 113 extending along proximal and distalends 115 a, 115 b of channels 115. In one embodiment, raised outerportions 113 include openings 113 a configured to receive two lengths ofsuture thread 11 adjacent to or on top of one another. As shown, suturenest 114 includes three channels 115; however, it is envisioned thatsuture nest 115 may include one or more channels 115. In one embodiment,suture nest 114 may be formed without a channel. In this manner, firstand second portions 13, 14 of suture thread 11 are received in opening113 a and are maintained adjacent to one another through the tensionapplied by suture tensioning means 125 (FIG. 3A).

Still referring to FIGS. 2A-2C, pin 116 a extends from pin retainingmember 116. Pin retaining member 116 is pivotally attached to platform112 such that pin 116 a may be selectively positioned and securelyretained perpendicular to channels 115 along an end thereof (FIG. 3B).Pin lock 118 is pivotally attached to suture nest 114 and is configuredto secure pin 116 a in the perpendicular position adjacent proximal end115 a of channels 115. Alternatively, pin lock 118 is integrally formedwith suture nest 114. In another embodiment, pin retaining member 116 isreleasably attached or securely affixed to platform 112. The diameter ofpin 116 a may be varied depending on the desired size of loop 12.

Turning briefly to FIG. 3A, as discussed above, system 100 also includessuture retaining means 120 and suture tensioning means 125. Sutureretaining means 120 may include a clamp or other device configured toretain a proximal end 11 a of suture thread 11. Suture tensioning means125 may include a hydraulic or pneumatic tensioning cylinder or othertensioning device configured to receive a distal end 11 b of suturethread 11 and to apply tension to suture thread 11 once thread 11 hasbeen securely received about pin 116 a. Suture retaining means 120 andsuture tensioning means 125 are positioned adjacent distal end 115 b ofchannel 115 to securely receive respective proximal and distal ends 11a, 11 b of suture thread 11 during the forming of loop 12.

With reference to FIGS. 3A and 3B, welding/cutting assembly 130 includesan ultrasonic device 132 operably connected to a generator (not shown)for ultrasonically vibrating a die 200 extending from ultrasonic device132. In one embodiment, welding/cutting assembly 130 is operativelymounted on a press assembly (not shown for approximating die 200 ofwelding/cutting assembly 130 towards and away from base 110, in thedirection of arrows “A₁”, to engage and disengage, respectively, thread11. The press assembly may further be configured to move welding/cuttingassembly 130 along thread 11, in the direction of arrows “A₂”. In analternative embodiment, welding/cutting assembly 130 is securely mountedrelative to base 110 and base 110 is raised and lowered with respect towelding/cutting assembly 130, in the direction of arrows “B₁”, and ismoved laterally with respect to welding/cutting assembly 130, in thedirection of arrows “B₂”. In another embodiment, either or both of base110 and welding/cutting assembly 130 are moved relative to each other.

With reference now to FIGS. 4A-4F, in one embodiment, die 200 defines asubstantially bolt like member 202 including a base 204 and a threadedextension 206. Threaded extension 206 is configured for operableengagement with a press (not shown). Base 204 is configured to beengaged by a wrench or other tool (not shown). In this manner, die 200may be replaced as necessary. A suture mount 210 extends from base 204and defines a channel 212 for receiving first section 13 of thread 11(FIG. 1A). Although shown including channel 212, it is envisioned thatbase 204 may instead form a substantially flat thread engaging surface.

Still referring to FIGS. 4A-4F, formed within channel 212, suture mount210 includes a thread engaging portion 214 and a thread cutting portion216. Thread cutting portion 216 includes a rounded edge 216 a having asubstantially flat cutting surface for severing the excess portion offirst section 13 of thread 11 and forming tapered surface 17. In analternative embodiment, edge 216 a may include a convex, concave and/orbeveled cutting surface for forming a concave, convex and/or beveledtapered surface 17. Thread engaging portion 214 of suture mount 210defines a substantially planar surface 214 a. in alternativeembodiments, thread engaging portion 214 of suture mount 210 may definea surface corresponding to the contour of suture thread 11. In thismanner, thread engaging portion 214 may include a concave, convex orbeveled surface to correspond with a suture thread having a convex,concave or beveled profile. It is further envisioned that threadengaging portion 214 may include one or more notches (not shown)configured to accommodate barbs (not shown) formed on thread 11. In thismanner, the barbs would be received within the notches formed in threadengaging portion 214 and not be flattened during the welding/cuttingprocess.

The method of forming looped suture 10 utilizing system 100 will now bedescribed with reference to FIGS. 3A and 5-6C. Referring initially toFIG. 3A, a proximal end 11 a of thread 11 is securely locked in a clamp120. Second section 14 of thread 11 is then positioned within a channel115 of nest 114. Thread 11 is next wrapped around pin 116 a before firstsection 13 of thread 11 is placed on top of or adjacent second section14. A distal end 11 b of thread 11 is then received in tension cylinder125. Tensioning cylinder 125 is then activated to tension thread 11within base 110. To prevent stretching of thread 11 during the formingof looped suture 10, and to thereby maintain the consistency andintegrity of thread 11, thread 11 may be formed of a pre-stretchedmaterial.

With particular reference now to FIGS. 5-6C, once first and secondsections 13, 14 of thread 11 are positioned adjacent one another,welding/cutting assembly 130 is approximated towards suture nest 114, inthe direction of arrow “A₁”, and laterally with respect to suture nest114, in the direction of arrow “A₂”. Alternatively, as discussed above,suture nest 114 may be moved relative to welding/cutting assembly 130,in the direction of arrows “B₁”, “B₂”. As welding/cutting assembly 130and suture nest 114 are approximated, first section 13 of suture thread11 is received within channel 212 of die 200. Ultrasonic device 132 maybe activated at any point during this process to ultrasonically vibratedie 200.

Continued approximation of die 200 toward suture nest 114 causes threadcutting portion 216 of suture mount 110 to engage first section 13. Theultrasonic vibration of die 200 permits thread cutting portion 216 toeasily cut through first section 13 as welding/cutting assembly 130 ismoved towards suture nest 114. The continued movement of die 200 causesthread engaging portion 214 to engage first section 13 of thread 11. Thedownward pressure exerted on first section 13 of thread 11 from thecontinued approximation of die 200 towards nest 114 (FIG. 6B), incombination with ultrasonic vibration of die 200, causes the contactingportions of first and second sections 13, 14 to heat and begin to melt.The melting of the contacting portions of first and second sections 13,14 causes first and second sections 13, 14 to fuse, thereby creatingjoined section 15. As thread contacting portion 214 engages firstsection 13 of thread 11 to form joined section 15, thread cuttingportion 216 completely severs distal end 11 b of thread 11 from theremainder of thread 11, thereby forming tapered surface 17. In analternate embodiment, thread cutting portion 216 only partially seversdistal end 11 b of thread 11 from the remainder of thread 11, therebyrequiring subsequent removal of the remainder thread.

The rate at which base 110 and/or welding/cutting assembly 130 areapproximated towards one another relative to the rate at which base 110and/or welding/cutting assembly 130 are laterally moved relative to oneanother effects angle α (FIG. 6C) of tapered surface 17. The slower base110 and/or welding/cutting assembly 130 moves laterally relative to theother with respect to the rate of respective, upward and/or downwardmovement of base 110 and/or welding/cutting assembly 130, the greater isangle α of tapered surface 17. The converse is also true. The rate oflateral movement of base 110 and/or welding/cutting assembly 130relative to the rate of respective, relative upward and/or down wardmovement, may be increased to lessen the angle α of tapered surface 17.

Once first and second sections 13, 14 of thread 11 are fused to createjoined section 15, welding/cutting assembly 130 is approximated awayfrom suture nest 114 and looped suture 10 is removed from pin 116 a.Suture 10 may include flash or debris (not shown) formed during thewelding/cutting process. The flash may need to be removed before loopedsuture 10 may be used.

Although the illustrative embodiments of the present disclosure havebeen described herein with reference to the accompanying drawings, it isto be understood that the disclosure is not limited to those preciseembodiments, and that various other changes and modifications may beeffected therein by one skilled in the art without departing from thescope or spirit of the disclosure. For example, it is envisioned thatloop forming system 100 may include more than one welding/cuttingassembly 130 to produce more than one looped suture 10 per activation.

1. A method of forming a loop in a thread, the method comprising thesteps of: providing a loop forming system including, a base for securelyretaining a thread to be formed and a welding/cutting assembly forforming a loop; securing a portion of the thread relative to the basesuch that a first section of the thread is maintained adjacent to asecond section of the thread; moving at least one of the welding/cuttingassembly and the base towards the other to fuse the first section ofthread to the second section of thread while simultaneously cutting atapered end on a proximal end of the first section of the thread; and,moving at least one of the welding/cutting assembly and the base awayfrom the other.
 2. The method of claim 1, wherein the welding/cuttingassembly further comprises a clamp for retaining a first end of thethread and a tensioning member for retaining a second end of the threadand applying tension to the thread.
 3. The method of claim 2, whereinthe step of securing the portion of the thread to the base includesclamping the first end of the thread in the clamp and clumping thesecond end of the thread in the tensioning member.
 4. The method ofclaim 2, wherein the step of securing the portion of the thread to thebase includes wrapping the thread about a pin to form the loop.
 5. Themethod of claim 1, wherein the welding/cutting assembly includes a diehaving a thread engaging portion and a thread cutting portion configuredto form the tapered end on the thread.
 6. The method of claim 1, furthercomprising the step of removing the formed suture from the base.
 7. Themethod of claim 6, further including the step of removing debris fromthe formed suture.
 8. The method of claim 1, wherein the base includesat least one channel tor receiving at least a portion of the secondsection of the thread.
 9. The method of claim 8, wherein the step ofsecuring the portion of the thread to the base includes receiving atleast the portion of the second section of the thread within thechannel.
 10. The method of claim 1, further including a step of movingat least one of the welding/cutting assembly and the base laterally withrespect to the other.